The current theory about Big Bang says that 'normal' matter, as opposed to antimatter, won because something (some say that neutrinos are responsible) happened that broke the balance between matter and antimatter, known as CP symmetry violation.
Nothing existed before, maybe even time (meaning that 'before' does not have any signification), and nothing happened else than the creation of the universe.
But I have never seen any explanation for the CP symmetry violation and about 'before the big bang'.
So how about this ? Big bang is not an event that happened only once, at the beginning, and in one single place, but it's a steady state. It always happens and will always happen, maybe in several different places, but because of CP symmetry it does not have any consequence. But one time (possibly due to an evolution of local physical parameters or physical constants provoked by previous big bangs) the CP symmetry got broken ... and we know the rest of the story ;-)
Was this theory ever presented before, and does it have any chance of being compatible with current knowledge in astrophysics ?